ONOS-3725 Adding ability to retain pending configs.

This allows up-load of configurations before their backing classes are registered by apps/subsystems.

 Validation and delegation of network config change events is deferred until the class registration.

Change-Id: Ifc9c97fbc86e764cb03cecb1f73f7191de3e7754
diff --git a/core/api/src/test/java/org/onosproject/net/config/NetworkConfigServiceAdapter.java b/core/api/src/test/java/org/onosproject/net/config/NetworkConfigServiceAdapter.java
index 7307258..562fe5c 100644
--- a/core/api/src/test/java/org/onosproject/net/config/NetworkConfigServiceAdapter.java
+++ b/core/api/src/test/java/org/onosproject/net/config/NetworkConfigServiceAdapter.java
@@ -74,17 +74,24 @@
     }
 
     @Override
+    public <S, C extends Config<S>> C applyConfig(String subjectClassKey, S subject, String configKey, JsonNode json) {
+        return null;
+    }
+
+    @Override
     public <S, C extends Config<S>> void removeConfig(S subject, Class<C> configClass) {
 
     }
 
     @Override
-    public void addListener(NetworkConfigListener listener) {
+    public <S> void removeConfig(String subjectClassKey, S subject, String configKey) {
+    }
 
+    @Override
+    public void addListener(NetworkConfigListener listener) {
     }
 
     @Override
     public void removeListener(NetworkConfigListener listener) {
-
     }
 }